declare
    object_exists exception;
    pragma exception_init (object_exists , -01430);
begin
	execute immediate 'ALTER TABLE SECRETARIA add RUT NUMBER(12)';
	execute immediate 'ALTER TABLE SECRETARIA add DIRSECRETARIA VARCHAR(60)';
	execute immediate 'ALTER TABLE SECRETARIA add CIUDAD VARCHAR(60)';
	exception when object_exists then null;
end;